Design, synthesis, spectroscopic characterization, single crystal X-ray analysis, in vitro α-amylase inhibition assay, DPPH free radical evaluation and computational studies of naphtho[2,3-d]imidazole-4,9-dione appended 1,2,3-triazoles.

In our quest to design and develop N/O-containing inhibitors of α-amylase, we have tried to synergize the inhibitory action of 1,4-naphthoquinone, imidazole and 1,2,3-triazole motifs by incorporating these structures into a single matrix. For this, a series of novel naphtho[2,3-d]imidazole-4,9-dione appended 1,2,3-triazoles is synthesized by a sequential approach involving [3 + 2] cycloaddition of 2-aryl-1-(prop-2-yn-1-yl)-1H-naphtho[2,3-d]imidazole-4,9-diones with substituted azides. The chemical structures of all the compounds are established with the help of 1D-NMR, 2D-NMR, IR, mass and X-ray studies. The developed molecular hybrids are screened for their inhibitory action on the α-amylase enzyme using the reference drug, acarbose. Different substituents present on the attached aryl part of the target compounds show amazing variations in inhibitory action against the α-amylase enzyme. Based on the type of substituents and their respective positions, it is observed that compounds containing -OCH3 and -NO2 groups show more inhibition potential than others. All the tested derivatives display α-amylase inhibitory activity with IC50 values in the range of 17.83 ± 0.14 to 26.00 ± 0.17 µg/mL. Compound 2-(2,3,4-trimethoxyphenyl)-1-{[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl]methyl}-1H-naphtho[2,3-d]imidazole-4,9-dione (10y) show maximum inhibition of amylase activity with IC50 value 17.83 ± 0.14 µg/mL as compared to reference drug acarbose (18.81 ± 0.05 µg/mL). A molecular docking study of the most active derivative (10y) is performed with A. oryzae α-amylase (PDB ID: 7TAA) and it unveils favourable binding interactions within the active site of the receptor molecule. The dynamic studies reveal that the receptor-ligand complex is stable as the RMSD of less than 2 is observed in 100 ns molecular dynamic simulation. Also, the designed derivatives are assayed for their DPPH free radical scavenging ability and all of them exhibit comparable radical scavenging activity with the standard, BHT. Further, to assess their drug-likeness properties, ADME properties are also evaluated and all of them demonstrate worthy in silico ADME results.

Characterizing the Effect of Amylase Inhibitors on Maltodextrin Metabolism by Gut Bacteria Using Fluorescent Glycan Labeling.

Diet-derived polysaccharides are an important carbon source for gut bacteria and shape the human gut microbiome. Acarbose, a compound used clinically to treat type 2 diabetes, is known to inhibit the growth of some bacteria on starches based on its activity as an inhibitor of α-glucosidases and α-amylases. In contrast to acarbose, montbretin A, a new drug candidate for the treatment of type 2 diabetes, has been reported to be more specific for the inhibition of α-amylase, notably human pancreatic α-amylase. However, the effects of both molecules on glycan metabolism across a larger diversity of human gut bacteria remain to be characterized. Here, we used ex vivo metabolic labeling of a human microbiota sample with fluorescent maltodextrin to identify gut bacteria affected by amylase inhibitors. Metabolic labeling was performed in the presence and absence of amylase inhibitors, and the fluorescently labeled bacteria were identified by fluorescence-activated cell sorting coupled with 16S rDNA amplicon sequencing. We validated the labeling results in cultured isolates and identified four gut bacteria species whose metabolism of maltodextrin is inhibited by acarbose. In contrast, montbretin A slowed the growth of only one species, supporting the fact that it is more selective. Metabolic labeling is a valuable tool to characterize glycan metabolism in microbiota samples and could help understand the untargeted impact of drugs on the human gut microbiota.

Acarbose diminishes postprandial suppression of bone resorption in patients with type 2 diabetes.

AIMS: The alpha-glucosidase inhibitor acarbose is an antidiabetic drug delaying assimilation of carbohydrates and, thus, increasing the amount of carbohydrates in the distal parts of the intestines, which in turn increases circulating levels of the gut-derived incretin hormone glucagon-like peptide 1 (GLP-1). As GLP-1 may suppress bone resorption, acarbose has been proposed to potentiate meal-induced suppression of bone resorption. We investigated the effect of acarbose treatment on postprandial bone resorption in patients with type 2 diabetes and used the GLP-1 receptor antagonist exendin(9-39)NH2 to disclose contributory effect of acarbose-induced GLP-1 secretion. METHODS: In a randomised, placebo-controlled, double-blind, crossover study, 15 participants with metformin-treated type 2 diabetes (2 women/13 men, age 71 (57-85 years), BMI 29.7 (23.6-34.6 kg/m2), HbA1c 48 (40-74 mmol/mol)/6.5 (5.8-11.6 %) (median and range)) were subjected to two 14-day treatment periods with acarbose and placebo, respectively, separated by a six-week wash-out period. At the end of each period, circulating bone formation and resorption markers were assessed during two randomised 4-h liquid mixed meal tests (MMT) with infusions of exendin(9-39)NH2 and saline, respectively. Glucagon-like peptide 2 (GLP-2) was also assessed. RESULTS: Compared to placebo, acarbose impaired the MMT-induced suppression of CTX as assessed by baseline-subtracted area under curve (P = 0.0037) and nadir of CTX (P = 0.0128). During acarbose treatment, exendin(9-39)NH2 infusion lowered nadir of CTX compared to saline (P = 0.0344). Neither parathyroid hormone or the bone formation marker procollagen 1 intact N-terminal propeptide were affected by acarbose or GLP-1 receptor antagonism. Acarbose treatment induced a greater postprandial GLP-2 response than placebo treatment (P = 0.0479) and exendin(9-39)NH2 infusion exacerbated this (P = 0.0002). CONCLUSIONS: In patients with type 2 diabetes, treatment with acarbose reduced postprandial suppression of bone resorption. Acarbose-induced GLP-1 secretion may contribute to this phenomenon as the impairment was partially reversed by GLP-1 receptor antagonism. Also, acarbose-induced reductions in other factors reducing bone resorption, e.g. glucose-dependent insulinotropic polypeptide, may contribute.

Hypoglycemic effect of the dry leaf extract of Myrcia multiflora in streptozotocin-induced diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Myrcia multiflora (Lam) DC. is a medicinal plant used in folk medicine for diabetes control, mainly in the Brazilian Amazon. The leaves of this species has already demonstrated antidiabetic properties; however, in mice with type 2 diabetes (DM2), the cumulative effect of the consumption of the dry extract of M. multiflora leaves (Mm) has not yet been reported. AIM OF THE STUDY: To investigate the effect of the dry extract obtained from the infusion of the dried leaves of M. multiflora on the blood glucose levels of diabetic mice. MATERIALS AND METHODS: DM2 was induced in Swiss male mice by a single intraperitoneal injection of streptozotocin [150 mg/kg body weight (bw)]. The animals were divided into two control groups (healthy and diabetic without treatment) and three sample groups that received Mm (25 and 50 mg/kg bw) and acarbose (200 mg/kg bw) by gavage once daily for 28 days (D28). Additionally, biochemical parameters, thiobarbituric acid reactive species (TBARS) levels in the liver, and histopathological analyses of the kidneys and liver were performed. RESULTS: On the seventh day of treatment, a 74.7% reduction in glucose levels were observed in the group of diabetic animals treated with Mm (50 mg/kg bw) when compared to the beginning of the treatment. At D28, the hypoglycemic effect was maintained. The results of the biochemical and histopathological parameters and the TBARS levels suggest that this dry extract exerts nephro- and hepatoprotective effects. CONCLUSIONS: The findings demonstrate the potential that this extract has to inhibit the α-glucosidase enzyme, and it acts similarly to the positive control acarbose. Furthermore, this extract is nephro- and hepatoprotective. Therefore, this dry extract has the potential to be an adjuvant for DM2, which corroborates its use in folk medicine.

Synthetic α-glucosidase inhibitors as promising anti-diabetic agents: Recent developments and future challenges.

Diabetes mellitus is one of the biggest challenges for the scientific community in the 21st century. It is a well-recognized multifactorial health problem contributes significantly to high mortality rates by causing serious health complications mainly related to cardiovascular diseases, kidney damage and neuropathy. The inhibition of α-glucosidase (enzyme that catalyses starch hydrolysis in the intestine) is an effective therapeutic approach for controlling hyperglycemia associated with type-2 diabetes. However, the presently approved drugs/inhibitors such as acarbose, miglitol and voglibose have several undesirable gastrointestinal side effects impeding their applications. Therefore, search for novel and more effective inhibitors with reduced side effects and less cost remains a fascinating area of research. In this context, a large variety of α-glucosidase inhibitors have been identified in recent years that demands attention from drug development community. This review is therefore an effort to summarize and highlight the promising α-glucosidase inhibitors especially those which are primarily based on aromatic heterocyclic scaffolds such as coumarin, imidazole, isatin, pyrimidine, quinazoline, triazine, thiazole etc, having improved safety and pharmacological profiles.

Acarbose May Function as a Competitive Exclusion Agent for the Producing Bacteria.

Acarbose is a well-known microbial specialized metabolite used clinically to treat type 2 diabetes. This natural pseudo-oligosaccharide (PsOS) shows potent inhibitory activity toward various glycosyl hydrolases, including α-glucosidases and α-amylases. While acarbose and other PsOSs are produced by many different bacteria, their ecological or biological role in microbial communities is still an open question. Here, we show that several PsOS-producing actinobacteria, i.e., Actinoplanes sp. SE50/110 (acarbose producer), Streptomyces glaucescens GLA.O (acarbose producer), and Streptomyces dimorphogenes ATCC 31484 (trestatin producer), can grow in the presence of acarbose, while the growth of the non-PsOS-producing organism Streptomyces coelicolor M1152 was suppressed when starch is the main source of energy. Further investigations using recombinant α-amylases from S. coelicolor M1152 and the PsOS-producing actinobacteria revealed that the S. coelicolor α-amylase was inhibited by acarbose, whereas those from the PsOS-producing bacteria were not inhibited by acarbose. Bioinformatic and protein modeling studies suggested that a point mutation in the α-amylases of the PsOS-producing actinobacteria is responsible for the resistance of those enzymes toward acarbose. Converting the acarbose-resistant α-amylase AcbE to its A304H variant diminished its acarbose-resistance property. Taken together, the results suggest that acarbose is used by the producing bacteria as a competitive exclusion agent to suppress the growth of other microorganisms in their natural environment, while the producing organisms equip themselves with α-amylase variants that are resistant to acarbose.

Alpha-glucosidase inhibitory activities of astilbin contained in Bauhinia strychnifolia Craib. stems: an investigation by in silico and in vitro studies.

INTRODUCTION: Bioactive compounds from traditional medicines are good alternatives to standard diabetes therapies and may lead to new therapeutic discoveries. The stems of Bauhinia strychnifolia Craib. (BC) have a possible antihyperglycemic effect; However, the extraction of astilbin from BC has never been recorded in alpha-glucosidase inhibitory activities. METHODS: Using liquid chromatography-mass spectrometry (LC-MS/MS), 32 compounds were detected in the BC extract. The screening was based on peak area. Seven compounds found. PASS recognized all seven compounds as potential alpha-glucosidase (AG) inhibitors. Astilbin and quercetin 3-rhamnoside were the most likely inhibitors of AG. Arguslab, AutoDock, and AutoDock Vina investigated the binding of the two compounds and AG. The binding stability was confirmed by molecular dynamics (MD). In addition, the optimum solvent extraction was studied via CosmoQuick, and extracts were examined with 1H-NMR prior to testing with AG. RESULTS: All three software programs demonstrated that both compounds inhibit AG more effectively than acarbose. According to the sigma profile, THF is recommended for astilbin extraction. The BC extract with THF showed outstanding AG inhibitory action with an IC50 of 158 ± 1.30 µg mL-1, which was much lower than that of the positive control acarbose (IC50 = 190 ± 6.97 µg mL-1). In addition, astilbin from BC was found to inhibit AG strongly, IC50 = 22.51 ± 0.70 µg mL-1 through the extraction method of large-scale astilbin with THF has the best extraction capacity compared to other solvents, hence the initial stage of extraction employs THF to extract and precipitate them with ethyl acetate and water. CONCLUSION: In silico and in vitro studies reveal that astilbin inhibits AG and is superior to acarbose, validating its promise as an AG inhibitor. Overall, astilbin was the most bioactive component of BC for antidiabetic action.

Triazole based novel molecules as potential therapeutic agents: Synthesis, characterization, biological evaluation, in-silico ADME profiling and molecular docking studies.

In this study, eight new compounds (7a-h) based on triazole compounds containing ester groups were synthesized with high yields. The structures of the synthesized compounds (7a-h) were elucidated by various spectroscopic methods (element analysis, FT-IR, 1H-(13C) NMR). Antioxidant, anticancer, and α-amylase enzyme inhibition activities of synthesized new triazole derivatives were carried out, and the effects of different groups on the activity were investigated. When the determined antioxidant properties of the compounds were examined, all synthesized compounds showed a moderate radical scavenging effect against radicals depending on the concentration (6.25-200 g/mL). All compounds except the three derivatives were found to have higher IC50 values than the standard drug acarbose (IC50: 891 µg/mL) according to the α-amylase enzyme inhibition results. Compound 7g (IC50: 50 g/mL) was discovered to have nearly eighteen (18) times the activity of the conventional medication acarbose (IC50: 891 µg/mL). Compounds synthesized for anticancer activity studies were screened against the Hela cell line, and the results were compared with standard cis-platinum (IC50: 16.30 µg/mL). Compound 7g (IC50: 19.78 µg/mL) was found to have almost the same activity as cis-platinum. Using Qikprop, the compounds were thoroughly tested for ADME qualities, and none violated any drug similarity standards. According to ADME data, whole physicochemical drug-likeness parameters of molecules remained within defined ranges as stipulated in the Lipinski rules (RO5) and revealed a high bioavailability profile. The molecular docking results with 2QV4 and 4GQR alpha-amylase enzymes demonstrated that all molecules have a high affinity, indicating polar and apolar interaction with critical amino acids in the α-amylase binding pocket.

New cycloalkyl[b]thiophenylnicotinamide-based α-glucosidase inhibitors as promising anti-diabetic agents: Synthesis, in silico study, in vitro and in vivo evaluations.

In the present study, a series of cycloalkyl[b]thiophenylnicotinamide derivatives against α-glucosidase were synthesized, and evaluated for their in vitro and in vivo anti-diabetic potential. Most of the synthetic analogues exhibited superior α-glucosidase inhibitory effects than the standard drug acarbose (IC50 = 258.5 µM), in which compound 11b with cyclohexyl[b]thiophene core demonstrated the highest activity with an IC50 value of 9.9 µM and showed higher selectivity towards α-glucosidase over α-amylase by 7.4-fold. Fluorescence quenching experiment confirmed the direct binding of 11b with α-glucosidase, kinetics study revealed that 11b was a mixed-type inhibitor, and its binding mode was analyzed using molecular docking. Moreover, analogs compounds 6a-9b, 11b, 12b did not show in vitro cytotoxicity against LO2 and HepG2 cells. Finally, compound 11b exhibited in vivo hypoglycemic activity by reducing the blood glucose levels in sucrose-loaded rats.

Acarbose, an α-Glucosidase Inhibitor, Maintains Altered Redox Homeostasis During Aging by Targeting Glucose Metabolism in Rat Erythrocytes.

Increasing age is the single largest risk factor for a variety of chronic illnesses. As a result, improving the capability to target the aging process leads to an increased health span. A lack of appropriate glucoregulatory control is a recurring issue associated with aging and chronic illness, even though many longevity therapies result in the preservation of glucoregulatory control. In this study, we suggest that targeting glucose metabolism to improve regulatory control can help slow the aging process. Male Wistar rats, both young (age 4 months) and old (age 24 months), were given acarbose (ACA) (30 mg/kg b.w.) for 6 weeks. An array of oxidative stress indicators was assessed after the treatment period, including plasma antioxidant capacity as determined by the ferric reducing ability of plasma (FRAP), reactive oxygen species (ROS), lipid peroxidation (malondialdehyde [MDA]), reduced glutathione (GSH), total plasma thiol (sulfhydryl [SH]), plasma membrane redox system (PMRS), protein carbonyl (PCO), advanced oxidation protein products (AOPPs), advanced glycation end products (AGEs), and sialic acid (SA) in control and treated groups. When compared with controls, ACA administration increased FRAP, GSH, SH, and PMRS activities in both age groups. The treated groups, on the contrary, showed substantial decreases in ROS, MDA, PCO, AOPP, AGE, and SA levels. The effect of ACA on almost all parameters was more evident in old-age rats. ACA significantly increased PMRS activity in young rats; here the effect was less prominent in old rats. Our data support the restoration of antioxidant levels in older rats after short-term ACA treatment. The findings corroborate the potential role of ACA as a putative calorie restriction mimetic.

Mechanistic Insight of Synthesized 1,4-Dihydropyridines as an Antidiabetic Sword against Reactive Oxygen Species.

The pharmacologically privileged DHP derivatives were synthesized using the pragmatic multicomponent Hantzsch synthesis to screen the antidiabetic activity. Initially, the candidates were screened using an in vivo blood glucose test, where compound 8b showed the most prominent antidiabetic effect (% potency = 218%) compared to glimepiride. Then, a propositioned structure-activity relationship study was executed to reveal that longer side chains decreased the DHP's antidiabetic action. Mechanistically, compound 8b diminished ROS in ß-cells and muscle cells simultaneously, which was proved by enhanced serum biochemical markers. Also, compound 8b decreased blood glucose by α-glucosidase inhibition (IC50 = 4.48 ± 0.32 µM), compared to acarbose (7.40 ± 0.41 µM), based selectively on the plasma window of 8b. Acarbose demonstrated auspicious inhibitor activity according to the binding affinity (ΔGbinding), which was slightly lower than that of compound 8b (-54.7 and -46.8 kcal/mol, respectively). During the 100 ns molecular dynamics simulations, the structural and energetic assessments exposed the high consistency of compound 8b to bind to the α-glucosidase.

Acarbose Protects Glucolipotoxicity-Induced Diabetic Nephropathy by Inhibiting Ras Expression in High-Fat Diet-Fed db/db Mice.

Diabetic nephropathy (DN) exacerbates renal tissue damage and is a major cause of end-stage renal disease. Reactive oxygen species play a vital role in hyperglycemia-induced renal injury. This study examined whether the oral hypoglycemic drug acarbose (Ab) could attenuate the progression of DN in type 2 diabetes mellitus mice. In this study, 50 mg/kg body weight of Ab was administered to high-fat diet (HFD)-fed db/db mice. Their body weight was recorded every week, and the serum glucose concentration was monitored every 2 weeks. Following their euthanasia, the kidneys of mice were analyzed through hematoxylin and eosin, periodic acid Schiff, Masson's trichrome, and immunohistochemistry (IHC) staining. The results revealed that Ab stabilized the plasma glucose and indirectly improved the insulin sensitivity and renal functional biomarkers in diabetic mice. In addition, diabetes-induced glomerular hypertrophy, the saccharide accumulation, and formation of collagen fiber were reduced in diabetic mice receiving Ab. Although the dosages of Ab cannot decrease the blood sugar in db/db mice, our results indicate that Ab alleviates glucolipotoxicity-induced DN by inhibiting kidney fibrosis-related proteins through the Ras/ERK pathway.

System Dynamic Model Simulates the Growth Trend of Diabetes Mellitus in Chinese Population: Implications for Future Urban Public Health Governance.

Objectives: To simulate the growth trend of diabetes mellitus in Chinese population. Methods: The system dynamic modeling methodology was used to establish a population prediction model of diabetes with or without cardiovascular diseases. Lifestyle therapy and the use of metformin, acarbose, and voglibose were assumed to be intervention strategy. The outcomes will be examined at 5, 15, and 30 years after 2020. Results: The projected number of diabetic population in China would increase rapidly from 141.65 million in 2020 to 202.84 million in 2050. Diabetic patients with cardiovascular disease would rapidly increase from 65.58 million in 2020 to 122.88 million by 2050. The annual cost for the entire population with diabetes mellitus in China would reach 182.55 billion by 2050. When the treatment of cardiovascular disease was considered, expenditure was 1.5-2.5-fold higher. Lifestyle therapy and the use of metformin, acarbose and voglibose could effectively slow the growth of the diabetic population. Conclusion: The diabetic population in China is expected to increase rapidly, and diabetic patients with cardiovascular disease will increase greatly. Interventions could delay it.

Design, Synthesis and Pharmacological Evaluation of 2-(3-BenzoyI-4-Hydroxy-1,1-Dioxido-2H-Benzo[e][1,2]thiazin-2-yI)-N-(2-Bromophenyl) Acetamide as Antidiabetic Agent.

Purpose: The present study is based on screening new and potent synthetic heterocyclic compounds as anti-diabetic drugs using various computational tools, lab experiments, and animal models. Methods: A potent synthetic compound 2-(3-benzoyl-4-hydroxy-1,1-dioxido-2H-benzo[e][1,2]thiazin-2-yl)-1-(2-bromophenyl) acetamide (FA2) was checked against diabetes and screened via enzyme inhibition assays, enzyme kinetics against alpha-glucosidase and alpha-amylase. Protein-ligand interaction was analyzed via molecular docking and toxicological analysis via ADMET. Experimental animals were used to examine the compound FA2 safety, delivery, and check various biochemical tests related to diabetes like fasting glucose sugar, cholesterol, triglyceride, HbAc1, creatinine, and insulin level. Histography of liver, kidney, and pancreas was also performed. Results: Results showed that FA2 had binding energy of -7.02 Kcal/mol and -6.6 kcal/mol against α-glucosidase (PDB ID: 2ZE0) and α-amylase (PDB ID: 1B2Y), respectively. Moreover, in vitro enzyme inhibition assays and enzyme kinetics against α-glucosidase and α-amylase were performed, and FA2 showed IC50 at 5.17 ± 0.28 µM and 18.82 ± 0.89 µM concentrations against α-glucosidase and α-amylase, respectively. Kinetics studies showed that the FA2 compound impeded α-glucosidase and α-amylase as a non-competitive mode of inhibition with Ki' values -0.320 ± 0.001 and 0.141 ± 0.01, respectively. FA2 was further analyzed on alloxan-induced mice for 21 days. Biochemical tests (fasting glucose sugar, cholesterol, triglyceride, HbAc1, creatinine, and insulin levels) and histological examination of liver and kidney showed that the FA2 compound showed better results than acarbose. Histology of pancreas found to show the maintenance of normal pancreatic acini and Langerhans islets in FA2 treated mice compared to acarbose and nontreated diabetic controls. Conclusion: Investigating anti-diabetic potential of FA2 compound showed that the selected benzothiazine derivative has tremendous importance in reducing dose concentration and side effects.

Enhancement of acarbose production by genetic engineering and fed-batch fermentation strategy in Actinoplanes sp. SIPI12-34.

BACKGROUND: Acarbose, as an alpha-glucosidase inhibitor, is widely used clinically to treat type II diabetes. In its industrial production, Actinoplanes sp. SE50/110 is used as the production strain. Lack of research on its regulatory mechanisms and unexplored gene targets are major obstacles to rational strain design. Here, transcriptome sequencing was applied to uncover more gene targets and rational genetic engineering was performed to increase acarbose production. RESULTS: In this study, with the help of transcriptome information, a TetR family regulator (TetR1) was identified and confirmed to have a positive effect on the synthesis of acarbose by promoting the expression of acbB and acbD. Some genes with low expression levels in the acarbose biosynthesis gene cluster were overexpressed and this resulted in a significant increase in acarbose yield. In addition, the regulation of metabolic pathways was performed to retain more glucose-1-phosphate for acarbose synthesis by weakening the glycogen synthesis pathway and strengthening the glycogen degradation pathway. Eventually, with a combination of multiple strategies and fed-batch fermentation, the yield of acarbose in the engineered strain increased 58% compared to the parent strain, reaching 8.04 g/L, which is the highest fermentation titer reported. CONCLUSIONS: In our research, acarbose production had been effectively and steadily improved through genetic engineering based on transcriptome analysis and fed-batch culture strategy.

Design, synthesis, spectroscopic characterization, computational analysis, and in vitro α-amylase and α-glucosidase evaluation of 3-aminopyridin-2(1H)-one based novel monothiooxamides and 1,3,4-thiadiazoles.

Due to the growth in the incidence of diabetes mellitus throughout the world, the urgency in the search for new safe and effective inhibitors of α-amylase and α-glucosidase is increasing. In this work, we attempted to carry out studies on the synthesis, modification and comprehensive computer and biological research of new derivatives of monothiooxamides. It was shown that monothiooxamides based on 3-aminopyridin-2(1H)-ones enter into transamidation reactions with hydrazine hydrate to form the corresponding thiohydrazides. Furthermore, under the action of chloroacetyl chloride and succinic anhydride, these thiohydrazides are cyclized into conjugated 1,3,4-thiadiazole derivatives. The possible biological activity of the obtained products was evaluated by molecular docking using the AutoDock Vina program. Compounds 7a and 8b showed higher binding affinities for selected target proteins compared to the known anti-diabetic drugs acarbose and TAK-875. The obtained new derivatives of 1,3,4-thiadiazole showed sufficiently high values of inhibitory activity in the in vitro test against the enzymes α-amylase and α-glucosidase as well as sufficiently low IC50 values (for 8b 122.2 µM), which is 8 times less than the value for the reference drug acarbose (998.3 µM). All synthesized derivatives of monothiooxamides 5-8(a-c) showed no cytotoxic properties at physiological concentrations in the MTT test in human neonatal dermal fibroblasts. Moreover, some compounds (6a-c, 7a-c, 8b,c) showed pronounced cytoprotective activity. Thus, the compounds 5-8(a-c) synthesized by us, both according to the results of computer calculations and in vitro biological screening, showed their potential antidiabetic activity and high prospects for further in-depth studies, including in vivo studies.

Synthesis, In Vitro Anti-Microbial Analysis and Molecular Docking Study of Aliphatic Hydrazide-Based Benzene Sulphonamide Derivatives as Potent Inhibitors of α-Glucosidase and Urease.

A unique series of sulphonamide derivatives was attempted to be synthesized in this study using a new and effective method. All of the synthesized compounds were verified using several spectroscopic methods, including FTIR, 1H-NMR, 13C-NMR, and HREI-MS, and their binding interactions were studied using molecular docking. The enzymes urease and α-glucosidase were evaluated against each derivative (1-15). When compared to their respective standard drug such as acarbose and thiourea, almost all compounds were shown to have excellent activity. Among the screened series, analogs 5 (IC50 = 3.20 ± 0.40 and 2.10 ± 0.10 µM) and 6 (IC50 = 2.50 ± 0.40 and 5.30 ± 0.20 µM), emerged as potent molecules when compared to the standard drugs acarbose (IC50 = 8.24 ± 0.08 µM) and urease (IC50 = 7.80 ± 0.30). Moreover, an anti-microbial study also demonstrated that analogs 5 and 6 were found with minimum inhibitory concentrations (MICs) in the presence of standard drugs streptomycin and terinafine.

Exploring Active Ingredients, Beneficial Effects, and Potential Mechanism of Allium tenuissimum L. Flower for Treating T2DM Mice Based on Network Pharmacology and Gut Microbiota.

Forty compounds were isolated and characterized from A. tenuissimum flower. Among them, twelve flavonoids showed higher α-glucosidase inhibition activities in vitro than acarbose, especially kaempferol. The molecular docking results showed that the binding of kaempferol to α-glucosidase (GAA) could reduce the hydrolysis of substrates by GAA and reduce the glucose produced by hydrolysis, thus exhibiting α-glucosidase inhibition activities. The in vivo experiment results showed that flavonoids-rich A. tenuissimum flower could decrease blood glucose and reduce lipid accumulation. The protein expression levels of RAC-alpha serine/threonine-protein kinase (AKT1), peroxisome proliferator activated receptor gamma (PPARG), and prostaglandin G/H synthase 2 (PTGS2) in liver tissue were increased. In addition, the Firmicutes/Bacteroidetes (F/B) ratio was increased, the level of gut probiotics Bifidobacterium was increased, and the levels of Enterobacteriaceae and Staphylococcus were decreased. The carbohydrate metabolism, lipid metabolism, and other pathways related to type 2 diabetes mellitus were activated. This study indicating flavonoids-rich A. tenuissimum flower could improve glycolipid metabolic disorders and inflammation in diabetic mice by modulating the protein expression and gut microbiota.

Growth differentiation factor 15 is not associated with glycemic control in patients with type 2 diabetes mellitus treated with metformin: a post-hoc analysis of AIM study.

BACKGROUND: Growth differentiation factor 15 (GDF15) was newly discovered to be a promising target of metformin. The study was aimed to investigate the relationship between GDF15 and glycemic control after metformin treatment in patients with type 2 diabetes mellitus. METHODS: The study was a post-hoc analysis of AIM (the effect of Acarbose on glycemic variability in patients with type 2 diabetes mellitus using premixed Insulin compared to Metformin) study. The participants were randomly assigned to 12 weeks of metformin (MET) or acarbose (ACA) treatment combined with insulin. Serum GDF15 levels of 51 subjects from MET group and 53 subjects from ACA group were measured at baseline and after a 12-week treatment. Fasting plasma glucose (FPG), 2-h postprandial plasma glucose (2-h PG) and glycated hemoglobin A1c (HbA1c) were measured at baseline and endpoint. RESULTS: After a 12-week treatment, serum GDF15 levels significantly increased in MET group [baseline vs. endpoint, 936.70 (741.00, 1205.40) pg/mL vs. 1265.20 (1027.90, 1634.00) pg/mL, P < 0.001], but not in ACA group [baseline vs. endpoint, 920.60 (701.45, 1332.55) pg/mL vs. 893.80 (663.25, 1284.05) pg/mL, P = 0.944]. However, there were no significant differences of glycemic control parameters (ΔFPG, Δ2-h PG and ΔHbA1c) between subgroups of MET group divided by median of ΔGDF15 (all P > 0.05). Spearman correlation coefficient and analysis of covariance after adjustment for baseline HbA1c levels showed that ΔGDF15 was not correlated with ΔFPG, Δ2-h PG and ΔHbA1c (all P > 0.05). CONCLUSION: Serum GDF15 levels were significantly elevated after metformin treatment in patients with type 2 diabetes mellitus. However, the increase was not an indicator of the glucose-lowering effect of metformin. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02438397 . Registered 8 May 2015.

Biochemical Characterization of GacI, a Bifunctional Glycosyltransferase-Phosphatase Enzyme Involved in Acarbose Biosynthesis in Streptomyces glaucescens GLA.O.

Acarbose, a pseudotetrasaccharide produced by several strains of Actinoplanes and Streptomyces, is an α-glucosidase inhibitor clinically used to control type II diabetes. Bioinformatic analysis of the biosynthetic gene clusters of acarbose in Actinoplanes sp. SE50/110 (the acb cluster) and Streptomyces glaucescens GLA.O (the gac cluster) revealed their distinct genetic organizations and presumably biosynthetic pathways. However, to date, only the acarbose pathway in the SE50/110 strain has been extensively studied. Here, we report that GacI, one of the proteins that appear to be different between the two pathways, is a bifunctional glycosyltransferase family 5 (GT5)-phosphatase (PP) enzyme that functions at two different steps in acarbose biosynthesis in S. glaucescens GLA.O. In the acb pathway, the GT and the PP reactions are performed by two different enzymes. Truncated GacI proteins having only the GT or the PP domain showed comparable catalytic activity with the full-length GacI, indicating that domain separation does not significantly affect their respective catalytic activity. GacI, which is widely distributed in many Streptomyces, represents the first example of naturally occurring GT5-PP bifunctional enzymes biochemically characterized.